is imprisoned in Indonesia, but Singapore, too, is draconian about these things. According to a Marine friend of mine, the caning is not a so big a deal: done over clothing*, exact regulations on location, force, etc, but the 20 years will be 20 years.
Long time.

*Wikipedia disagrees. Says Judicial Caning in Singapore is done on bare buttocks and in private. Not what my friend described to me. Will have to ask him for more details.